Forum on Benford’s law and statistical methods for the detection of frauds

Statistical Methods & Applications -     

Variability of water quality,metals and phytoplankton community structure in urban stormwater ponds along a vegetation gradient

Stormwater Ponds (SPs) are common throughout urbanizing environments, yet their ecological role has not been well established. SPs are primarily designed for hydrological control of stormwater, but many are also designed to attenuate the quality of runoff prior to discharge. Thus, SPs likely serve as an important land-water linkage between terrestrial and aquatic systems in urban areas. In this study, we characterized 22 SPs and 3 natural reference ponds from Durham Region, Ontario, Canada representing a gradient in emergent plant cover. There was high variability and wide ranges in water quality parameters among SPs. The percentage of impervious surface served as a measure of urbanization intensity, and was a significant driver of conductivity, chloride and total suspended solids regardless of emergent vegetation cover. In fact, only water temperature (r?=??0.61) was found to significantly correlate with vegetation cover. This suggests a minimal role for emergent vegetation in mediating SP water quality. SPs had notably higher conductivity and runoff-metals (Cu, Zn, Pb, and Cr) than reference ponds, but nutrients (Total P and Total N) and algal biomass did not significantly differ between SPs and reference ponds. Dominant phytoplankton groups included blue-green and euglenid algae, both of which are indicators of eutrophic and high organic systems, respectively. The blue-green genus Microcystis was detected in all ponds, and was the dominant taxon in most SPs. This raises concern that SPs may serve as reservoirs of toxin-producing algae. Multivariate analyses of metals, water quality variables and algal species composition showed considerable dissimilarity among SPs, yet comparably high similarity among reference ponds. This indicates that SPs are dynamic and diverse systems despite their engineered origins. Such broad gradients in water quality characteristics also imply variable impacts to receiving waters in the same region.     

A systematic review of the relationship between urban agriculture and biodiversity

Urban agriculture is a unique form of agriculture that can provide fresh, local produce for urban residents, and may benefit biodiversity by decreasing the need to expand agriculture into natural areas as well as enhancing biodiversity in urban areas. However, although urban agriculture is also often cited as promoting biodiversity in urban areas, the extent of empirical evidence for such claims has not been studied. Here we systematically review the relationship between urban agriculture and biodiversity in the scientific literature. We strictly define urban agriculture as areas in cities that grow produce specifically for human consumption. We examined 148 papers from 2000 to 2017, of which only 24 studies fit our definition of urban agriculture, and of those, only 18 both involved urban agriculture and measured biodiversity. Of the studies that did measure biodiversity, some showed increases in diversity compared to urban vacant lots, but other showed no difference. Moreover, these studies were mostly focused on plants and invertebrates and were conducted almost exclusively in North America. In order to use the generalization that urban agriculture will have a positive influence on urban biodiversity, more studies will need to be conducted across a wider geographic range worldwide (particularly in developing countries in the tropics) and on a greater diversity of species and taxa (e.g., herpetiles, birds and small mammals). Such studies will likely increase in conservation importance as urban expansion and agricultural demands increase globally.     

Fear of crime and participation in associational life

Fear of crime is studied extensively as a potential contributor to the decline of a community. People who fear crime are expected to stay indoors and seek shelter, which then encourages more crime, setting in motion a vicious cycle that ultimately bodes ill for community engagement. However, there is little research that examines directly the relationship between fear of crime and participation. We explore such a relationship with Canadian survey data by looking at whether fear of crime can explain participation in a variety of associational activities. Our models show a relationship between fear of crime and participation, but the nature of that relationship varies according to the type of activity. A high level of fear, as well as reciprocity, explain participation in “vertical” associational life, while the absence of fear explains participation in “horizontal” associational life, although this latter pattern is mediated through reciprocity.     

Strategy and Structure in High-Performing Nonprofits: Insights from Iberoamerican Cases

Some nonprofits evolve from small into large international organizations. For years, “structure follows strategy” (Chandler) has been the dictum to explain organizational strategic changes like the ones in nonprofits. But scholars also recognized organization structure to be a precondition to carry out certain strategies. Nevertheless, research on structure and strategy in nonprofits is limited. This paper explores the mutual influence of organization structure and strategy in high-performing nonprofits in Iberoamerica based on a secondary analysis of 20 unpublished research cases of the Social Enterprise Knowledge Network. It follows the research question: Which organizations’ strategies and structures characterize high-performing nonprofits over time? Four types of organizing patterns emerged: starting-up, professionalizing, decentralizing, and conglomerating.     

Rise and Fall of Sleep Quantity and Quality With Student Experiences Across the First Year of University

Covariations of self‐reported sleep quantity (duration) and quality (disturbances) with affective, stressful, academic, and social experiences across the first year of university in 187 Canadian students (M age=18.4) were examined with multilevel models. Female students reported sleeping fewer hours on average than did male students. In months when negative affect and general levels of stress were higher, sleep quantity was lower. Poorer sleep quality was seen in students living away from home and reporting more financial stress at baseline. In addition, sleep quality was poorer in months when negative affect and general levels of stress were higher (attenuating the effect of financial stress) and better in months when students spent more days with friends. Three themes are presented to explore the mechanisms by which sleep quantity and quality rise and fall in tandem with experiences of the first year of university.     

Roles,race and subjective well-being: A longitudinal analysis of elderly men

The basic contention of this paper is that research on subjective well-being would benefit from an integration of theory and research from other studies of subjective states, such as mental and physical health. Toward that end, we present results of an analysis of the impact of race and social roles on subjective well-being in a nationally representative sample of elderly men. The findings demonstrate that particular role configurations have an effect on happiness and that these effects are different for blacks and whites. Theoretical implications of these findings for subjective well-being research and role accumulation theory are discussed.     

Awareness of Listeriosis and Methylmercury toxicity public health recommendations and diet during pregnancy

Background

Awareness of Listeriosis and Methylmercury toxicity recommendations are associated with decreased intake of high-risk foods. Whether awareness of the recommendations affect dietary quality of pregnant women in Australian is unknown.